In this paper, the performances of a new delta -doping field-effect transistor utilizing an InGaP/GaAs camel-gate structure by theoretical and experimental analysis will be reported, An analytical model related to drain saturation current, transconductance, potential barrier height, gate-to-source depletion capacitance, and unit current gain frequency is developed to explain the device performances. The employments of n(+)-GaAs/p(+)-InGaP/n-GaAs heterostructure gate and the delta -doping channel with heavy-doping level were used to improve transconductance linearity and enhance current drivability. For a 1 x 100 mum(2) device, the experimental results show that a drain saturation current of 1120 mA/mrn, a maximum transconductance of 240 mS/mm, and a large V-gs swing larger than 3.5 V with the transconductance higher than 200 mS/nim are obtained. In addition, the measured unit current gain frequency f(t) is 22 GHz. These experimental results are consistent with theoretical analysis.